THE SPECTRUM OF THE FINAL DECAY OF LOCALIZED DISTURBANCES IN A VISCOUS FLUID,

Abstract

Based on previous work of Batchelor and Phillips it is shown that in an unbounded viscous fluid any decaying localized disturbance with a negligible nonlinear inertial force consists of a spectrum of dissipating spherical vortices. All these vortices can be derived from decaying multipoles. Such disturbances are characterized by a vorticity field which originates from a point source of vorticity and vanishes exponentially far away from its center. The result has been obtained by a Taylor-series expansion of the vorticity about the origin in a wave-number space. Vorticity fields which are produced in an extended region and over a finite period of time can be described by superposition. An example is given for decaying axisymmetric spherical discontinuity surfaces. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1968
Accession Number
AD0673533

Entities

People

  • Hans J. Lugt

Tags

DTIC Thesaurus Topics

  • Axisymmetric
  • Diffraction
  • Discontinuities
  • Mathematical Analysis
  • Mathematics
  • Sequences
  • Sequences (Mathematics)
  • Series (Mathematics)
  • Spectra

Fields of Study

  • Physics

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Fluid Dynamics.
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Space
  • Space - Hall-Effect Thruster